5-Hydroxytryptamine induces contraction in isolated human mammary artery: effect of ketanserin.
5-hydroxytryptamine (5HT) treatment produced dose-related contractions in the human internal mammary artery with an EC50 value of 3.4 X 10(-7) M. The 5HT2 receptor antagonist ketanserin reversed the contractions evoked by 5HT in a competitive manner at a low concentration (10(-8) M), whereas a noncompetitive antagonism was apparent at higher concentrations (5 X 10(-8) M to 5 X 10(-7) M). The alpha 1-blocking component of ketanserin was evaluated by studying the effect of ketanserin upon the contractile response evoked by norepinephrine. Up to 10(-7) M, ketanserin did not influence norepinephrine-induced contractions. These findings indicate that the mammary artery is a vascular tissue sensitive to contractions induced by 5HT and that the drug ketanserin antagonizes this contractile response through the 5HT2 receptor subtype.
Monopoli
A
A
Research Laboratories, Schering-Plough SpA, Milan, Italy.
Conti
A
A
Forlani
A
A
Ongini
E
E
Antona
C
C
Biglioli
P
P
D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007650:Ketanserin / Q000494:pharmacology*; D008323:Mammary Arteries / Q000187:drug effects / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists
D012702:Serotonin Antagonists; D012701:Serotonin; D007650:Ketanserin; D009638:Norepinephrine